Magneto electric device and electrical connection and mounting therefor



Nov. 26, 1957 T. TOGNOLA 2,814,742

MAGNETO ELECTRIC DEVICE AND ELECTRICAL CoNNECTIoN AND MOUNTING THEREFOR Filed Sept. 30, 1955 INVENTOR. TULLIO TOGNOLA A TTORNEYS United States Patent M MAGNETS ELECTREC DEVECE. AND ELECTRICAL CONNECTEQN AND MOUNTING THEREFOR Tnllio Tognola, Sidney, N. Y., assignor to Bendix Aviation Corporation, Sidney, N. Y., a corporation of Delaware Application September 30, B55, Serial No. 537,821

18 Claims. (Cl. 310-26) This invention relates to magneto electric apparatus and more particularly to devices of the so-called magnetostrictive type, electrical connecting means adapted for use in combination therewith and mounting means therefor.

One of the objects of the present invention is to provide a novelly constructed vibration pick-up or impact detecting device whereby electrical signals are generated in response to vibrations or other impacts to which the device is subjected.

Another object of the invention is to provide novel means for easily and quickly connecting a device of the above character and similar devices to and disconnecting the same from an electrical circuit.

Another object is to provide novel means for mounting a device of the above character, whereby the same may be readily and quickly attached to and detached from a structure such as the cylinder of an internal combustion engine or the like.

Another object of the invention is to provide novel connector means for electrical conductors, which means are so constructed as to permit ready and quick connection and disconnection.

A further object is to provide a novel type of electrical connector which is dependable in use and which embodies mating parts held together by magnetic force.

A still further object is to provide novel apparatus of the magnetostrictive type wherein the magnetized element is employed in a novel manner to mount the apparatus.

The above and further objects and novel features of the invention will more fully appear from the following detail description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is for purposes of illustration only and is not intended as a definition of the limits of the invention.

In the drawing, wherein like reference characters refer to like parts throughout the several views,

Fig. 1 is a sectional elevation view illustrating one form of vibration pick-up embodying the present invention;

Fig. 2 is a similar view of another form of vibration pick-up embodying the invention; and,

Fig. 3 is a similar view, only partly in section, showing another means for mounting the devices of Figs. 1 and 2.

Several embodiments of the invention are illustrated in the accompanying drawing, by way of example, in the form of vibration pick-up devices of the type usable in detecting the vibrations of engine cylinders, such as the vibration caused by the closing of valves, detonation of a gaseous charge, and the like. These devices when employed on an engine cylinder generate electrical signals in response to vibrations or similar impacts communicated thereto, and these signals may be utilized in studying and analyzing the operation of the engine in a manner well understood in the art. It will be understood, however, that devices embodying the invention are not limited to this particular use.

I 2,814,742 Patented Nov. 26, 1957 ICQ 1n the embodiment illustrated in Fig. 1, the electrical energy generating means is mounted within a metallic housing comprising a tubular shell 10 having an internal annular flange 11 intermediate the ends thereof. A ring 12 of non-magnetic metal or other material is seated against the lower face of flange 11, as viewed in the drawings, and has an annular portion 14 which fits within said flange and has the end surface thereof substantially flush with the upper face of the flange. A second metallic ring 15 fits within non-magnetic ring 12 with its upper face flush with the upper face of flange 11. The rings 12 and 15 are preferably silver soldered or otherwise intimately secured together and the resulting unit is preferably similarly secured within shell 10. The upper surfaces of flange 11 and unit 12, 15 may be machined flush after assembly. The lower ends of rings 12 and 15 are also preferably machined flush with each other. An inverted insulating cup 18 is fitted into the central opening in ring 15 and held therein by an external shoulder. Centrally located within shell 10 and seated in a counterbore in the lower face of ring 15 is a permanent magnet 1@ which has a North pole N and a South pole S.

The parts hereinabove described may be held in assembled relation with magnet 19 in firm contact with ring 15 by means of a metallic plug or end piece 21 which operatively engages internal threads in shell 10 and makes direct magnetic flux conducting contact with magnet 19. Substantially filling the space within shell 10 around magnet 19 is a coil 22 of insulated wire wound on a channel-shaped insulating spool 23. One end of coil 22 may be grounded to shell 10 and the other end 24 extends through a radial slot in the lower face of ring unit 12, 15. The tip end of conductor 24 has the insulation removed, extends through a small hole in cup 18 and is suitably connected to a washer or like terminal 25. End closure 21 may be locked in position, such as by a pin .26, and is preferably provided with an integral threaded stud or post 343 by means of which the unit may be satisfactorily mounted on an engine cylinder or the like.

For the purpose of dependably and quickly connecting coil 22 into and disconnecting the same from an electrical circuit, the present invention contemplates making novel, supplemental use of the magnet 19. This result is accomplished by what may be called a magnetic quickdisconnect which, in the form shown, comprises a metallic plunger 27 that slidably fits into the upper end of shell ltl and seats flush against the upper face of ring 15 and flange 11, bridging the interposed portion 14 of nonmagnetic ring 12. Preferably, a ring or collar 28 of non-magnetic material is provided around at least the inner end of plunger 27 for the purpose of directing and concentrating the lines of magnetic flux emanating from magnet 1S. An insulator 29 is seated within a counter-bore in plunger 27 and is in turn counter-bored and perforated to receive the conductive core 31 of an insulated cable 32. A helically coiled ribbon spring or similar terminal 33 is secured to conductor 31 for making electrical contact with terminal 25 whenever plunger 27 is in its socket in shell 10.

If desired, cable 32 may be surrounded by a flexible metallic conduit 34, the end of which may be suitably secured as by silver soldering within a hollow boss 35 on plunger 27.

The embodiment illustrated in Fig. 2 differs from the device of Fig. 1 primarily in that it includes a pin and socket type connection between the coil and the external circuit. As shown, said embodiment comprises a tu bular metallic shell 40 having a shoulder 41 and a reduced bore 42 at one end. A ring 43 of non-magnetic material secured within a metallic ring 44, an insulating cup 45, a coil 46, an insulating spool 47, a magnet 39, and an end closure ili correspond with and are combined within housing 43 in a cooperative manner similar to parts 12, 15, 18, 22, 23, 19, and 21, respectively, of Fig. l.

A male pin contact 49 extends upwardly from and has its'lower-end rigidly cemented orotherwise securedwithin insulating cup 45. As in the first embodiment, one end of coil 46 is grounded to shell4-0-and the other end is connected by an insulated conductor 50 to the end of pin-contact 49. The latter fits into a socket contact 51 which may be of the type illustrated in U. S. Patent No. 2,716,744 or of any other suitable known type and is connected at its outer end to an insulated conductor 52. The socket contact 51 is carried within a metallic plunger 53 which has a sliding fit in-the reduced bore 42 of housingor shell 40. The inner end of plunger 53 is adapted to engage the upper face of ring for a purpose to hereinafter appear.

The inner end of conductor 52' has a terminalcap 54 secured thereto and the latter is insulated from the plunger by an insulating ring 55'seated against an annular flange 56 in the plunger. Socket contact 51 is insulated from plunger 53 by means of a sleeve 57, the inner end of which abuts-against a flange 58 on the end of' said contact to hold the latter in position. A ring nut 59 threaded into plunger 53 holds the parts in assembled relation. If desired, insulated conductor 52 may be surrounded by a flexible shielding conduit 6t), the end of which may be soldered or otherwise suitably secured to plunger 53.

It will be seen that no mechanical means are provided in either of the above described embodiments of the invention for retaining plungers 27 and 53 in position to effect the electrical connection between coil 22 or 46 and the outgoing cable 32 or 52, respectively. This is accomplished in a novel manner by making use of the permanent magnetism of magnets 19 and 39 without appreciably affecting the functioning thereof in the generation of electrical energy in said coils in response to vibrations or other impacts. In the embodiment of Fig. 1 the path of the lines of magnetic flux emanating from the north pole N of the magnet is through ring or pole piece 15, plunger 27, shell and closure piece 21 to the south pole S of the magnet. Thus, the magnetism of magnet 19 is utilized to hold the mating parts of the connector together without appreciably reducing the effectiveness of the magnetic field in causing current flow in the coil When the device is subjected to shock. The pull required to separate the matingparts of the connection is determined by several factors, such as the strength of the magnet, the area of the contacting surfaces, the kinds of metal used, and others, and hence, the pull can be desirably adjusted by careful design.

In the embodiment of Fig. 2, the magnetic flux path is from the-north pole of the magnet through ring or pole piece 44 into plunger 53 and thence across the clearance space around the plunger into shell 4i), following the dotted line to theother pole of the magnet. It is desirable to keep the clearance between the shell and plunger quite small in order to insure apositive area of contact between the end or face of the plunger and the magnetic pole piece 44.

The operation of devices of the above character is well known in the art. When the unit and particularly the magnet element 19 or 39 is subjected to a series of impacts, such as by the vibrations of an engine cylinder, the magnetic field emanating therefrom is varied. This variation of the magnetic field in which-the coil 22 or 46 is wound creates current flow or a variation in the current flow in the circuit containing the coil. The current or voltage thus generated in the coil bears determinable relationships, such as in magnitude, frequency, timing, and the like, to the vibrations and hence, may beused for purposes of analysis. This basic function-of theillustrated devices is notappreciably affected by-thesimultaneous use of the field of the magnet for holding the mating parts of the described electrical connection together.

There is also illustrated in Fig. 3 novel means for making further supplemental use of the magnet 19 or 39 for mounting the units of Figs. 1 and 2 and similar devices when it is desired that the same be adapted for ready and quick attachment and detachment. As shown, the lower end closure for the shell 70 is fabricated from a non-magnetic metal ring 71 that underlies the coil and a pole shoe 72 of magnetic metal. The latter is integrally secured within the center opening and a counterbore in ring 71, such as by silver soldering, and is preferably counter-bored itself to provide an axial annular flange 73.. End closure 71, 72 is threaded into the shell and the end faces of the shell and closure unit are machined flush. To facilitate assembly and disassembly the outer or lower surface of the shell closure unit may be slotted, such as at 74, for reception of a suitable tool.

The device of Fig. 3 may be mounted in an adaptor 75 which may be permanently or removably secured to an engine cylinder or-other structure in any desired manner. The adaptor, in the form shown, consists of a cupshaped or socket portion 76 of magnetic metal and a threaded stud 77. Shell 70 has a close sliding fit in the adaptor and the end faces of the shell and pole shoe 72 have good magnetic flux conducting engagement with the bottom of socket portion 76. Thus, the magnetic flux path from the north pole of the magnet to the south pole includes-shell 70, adaptor 75 and the pole piece 72 as indicated by dotted lines. Thus, the magnetism of the magnet is effective to securely hold the magnetostrictive unit inadaptor 75 so that the same may very quickly be mounted and dismounted.

That portion of the device of Fig. 3 shown in elevation may be constructed in the same manner as the corresponding parts of the structure illustrated in either Fig. 1 or Fig. 2 01' in any other manner known to the art.

There is thus provided novelly constructed magnetostrictive apparatus wherein the permanent magnet element is employed in a novel and useful manner to perform a plurality of functions. Novel use is made of the magnetism to provide a quick electrical connection to an electrical circuit and also to provide a quick detachable mechanical connection or mount for the apparatus itself, this use being accomplished without the necessity of appreciably interfering with the normal operation of the apparatus as a magnetostrictive device. The device provided is of simple, yet sturdy construction which may be fabricated quickly and inexpensively from a small number of parts.

Although only a limited number of embodiments and modifications of the invention have been illustrated in the drawings and described in detail in the foregoing specification, it is to be expressly understood that the invention in its broadest scope is not so limited. For example, the apparatus or adaptor 75 may be bolted or otherwise secured in operative position in lieu of being mounted by a threaded stud. The non-magnetic parts, such as parts 12, 28, 43, and 71 are hatched for and described as beingmetallic but other suitable non-magnetic materials may be used. Various other changes, such as in the design and arrangement of the parts illustrated, may also be made without departing from the spirit and scope of the invention, as will now be understood by those skilled in the art.

What is claimed is:

1. Magneto electric apparatus comprising a permanent magnet of magnetostrictive material, a coil surrounding said magnet, a casing surrounding said magnet and coil, said casing comprising a ring of non-magnetic material creating an annular gap in the magnetic flux path between the poles of said magnet through the walls of said casing, said magnetic means being firmly clamped between opposite ends of said casing, whereby when the apparatus is subjected to shock the flow of electrical energy through said coil is varied, and electrical connector means for connecting an electrical conductor to said coil, said connector means comprising a magnetic flux conducting metallic member surrounding said electrical conductor and bridging said annular gap, whereby said connector means is held in operative position by the magnetic attraction of said magnet.

2. Apparatus as defined in claim 1 wherein said casing has a socket portion for slidably receiving said member.

3. Apparatus as defined in claim 1 wherein said member contacts said casing in the same plane on opposite sides of said annular gap.

4. Apparatus as defined in claim 1 wherein said member contacts said casing in one plane on one side of said gap and in a different plane on the other side of said gap.

5. Magneto electric apparatus comprising a permanent magnet, a coil surrounding said magnet, a casing surrounding said magnet and coil, said casing comprising two rings of non-magnetic material creating two annular gaps in the magnetic flux path between opposite poles of said magnet through the walls of said casing, magnetic flux conducting means for supporting said casing, said last-named means bridging one said gap, whereby said casing is held on said supporting means by the magnetic attraction of said magnet, magnetic flux con ducting means for bridging the other said gap, and electrical connector means carried by said last-named flux conducting means.

6. Apparatus as defined in claim 5 wherein said supporting means is cup-shaped to form a socket for slidably receiving said casing.

7. In electrical apparatus a magnet, a casing forming a magnetic flux path between opposite poles of said magnet, means creating a gap in said magnetic flux path in the walls of the casing, magnetic flux conducting means bridging said gap, whereby the same is attracted by said magnet, said last-named means constituting a supporting means for said casing, means for creating a second gap in said magnetic flux path, magnetic flux conducting means for bridging said second gap, whereby the same is attracted by said magnet, and electrical connector means carried by said last-named flux conducting means.

8. Apparatus as defined in claim 7 comprising a coil around said magnet in the casing, at least one end of said coil being detachably connected to said connector means.

9. In electrical apparatus, a magnet of magnetostrictive material, a coil surrounding said magnet, means forming a magnetic flux conducting path between opposite poles of said magnet, non-magnetic means creating a gap in said magnetic flux path through said first-named means, and magnetic flux conducting means bridging said gap, whereby the same is attracted by said magnet, the latter being firmly clamped between portions of and supported by said first-named means, whereby when the apparatus is subjected to shock the ilow of electrical energy through said coil is varied.

10. Electrical apparatus as defined in claim 9 comprising electrical connector means carried by said gap bridging means.

11. Electrical apparatus as defined in claim 9 wherein said magnetic flux conducting means constitutes supporting means for said first-named means.

12. Electrical apparatus as defined in claim 11 comprising means for creating a second gap in said magnetic flux path through said first-named means, magnetic flux conducting means for bridging said second gap, whereby the same is attracted by said magnet, and electrical connector means carried by said last-named flux conducting means.

13. Electrical apparatus as defined in claim 12 wherein said coil is detachably connected to said connector means.

14. Apparatus as defined in claim 5 wherein at least one end of said coil has electrical contact with said connector means.

15. Apparatus as defined in claim 14 wherein said magnet is of magnetostrictive material and is firmly clamped between opposite ends of said casing, whereby when the apparatus is subjected to shock the flow of electrical energy through said coil is varied.

16. Apparatus as defined in claim 5 wherein said rings form parts of the end walls of said casing.

17. Apparatus a defined in claim 16 wherein said magnet is of magnetostrictive material and is firmly clamped between said end walls, whereby when the apparatus is subjected to shock the flow of electrical energy through said coil is varied.

18. in electrical apparatus a magnet of magnetostrictive material, a coil surrounding said magnet, a casing forming a magnetic flux path between opposite poles of said magnet, means creating a gap in said magnetic flux path in the walls of the casing, and magnetic flux conducting means bridging said gap, whereby the same is attracted by said magnet, said magnetic flux conducting means constituting supporting means for said casing and said magnet being firmly clamped between opposite ends of said casing, whereby when the apparatus is subjected to shock the flow of electrical energy through said coil is varied.

References Cited in the file of this patent UNITED STATES PATENTS 1,658,945 Schenck Feb. 14, 1928 1,667,766 Bing May 1, 1928 2,275,839 Boehne Mar. 10, 1942 2,348,967 Duby May 16, 1944 

